Ptolemy's Tetrabiblos names the Sun and Saturn for the father, and the Moon and Venus for the mother, in every chart. That much does not change. What changes is which planet in each pair the tradition asks you to watch.
Ptolemy's rule. "We must observe by day particularly the Sun and Venus, and by night Saturn and the Moon" (Tetrabiblos III.4, "Of Parents"). By day, the Sun leads for the father and Venus leads for the mother. By night, Saturn leads for the father and the Moon leads for the mother.
This sentence closes a passage about the parents' fortunes, not a stand-alone law, so Celestium names it as Ptolemy's rule rather than flattening it into "the tradition says." Vettius Valens reads the choice differently: in the Anthologies, he has you watch whichever of the Sun or Saturn the Moon is actually configured with, regardless of day or night. The authors differ; the toggle below follows Ptolemy's rule, named as his.
Try it: day birth or night birth
Toggle between a day chart and a night chart for the same place and the same date, one at local noon and one at local midnight. Watch which pair takes the lead.
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Positions computed by the Celestium engine for New York, NY, October 19, 2026 (not by this page at runtime); see the data embedded below.
The fourth place
Vettius Valens names the fourth place, the one under the midheaven, "the Place of Parents" outright. Dorotheus adds that the ruler of that place, by sign, indicates the matter of the parents, apart from whichever significator leads by sect. A chart's parents are read through more than one door.
What this is, and is not
This is a description, not a verdict on anyone's actual mother or father. A chart shows a symbolic pair of significators and their condition. What it says about your own parents is a question to sit with, not a diagnosis to accept.
See your own chart's sect
Celestium computes your sect, your 4th place, and the Lots of the Father and Mother from your real birth data, on your device.
Read the prose version of this same material: Day and night charts and the parents.